1. Field of the Invention
This invention relates to a recording and reproducing apparatus, and more specifically, to a recording medium loading mechanism for bringing a recording medium to the recording or reproducing position.
2. Description of the Related Art
Lately, video apparatuses have made rapid progress. Above all, the electronic still video camera, which is capable of recording still images, sound, data or the like on a rotating magnetic disk and immediately effecting the reproduction, transmission, printing, etc., of what is thus recorded, has attracted considerable attention as the video apparatus which is to take the place of the conventional silver-halide camera.
As will be described in the description of the preferred embodiments of this invention, the electronic still video camera uses a magnetic disk sheet called a video floppy disk which is rotated at high speed. A magnetic head is brought into contact with this rotating disk, thereby effecting recording and reproduction.
Thus, the contact between the magnetic head and the magnetic disk must be constantly kept stable with high accuracy. In view of this, a stabilizing member is arranged on the opposite side of the magnetic head with respect to the magnetic disk and in close proximity to the head. This stabilizing member is adapted to utilize the airflow caused by the rotation of the magnetic disk for generating a pressure (hereinafter referred to as "positive pressure") for pressing the magnetic disk against the magnetic head, thereby stabilizing the touch of the magnetic head.
An apparatus of this type is further equipped with a loading mechanism which is adapted, when loading the magnetic disk on the rotating spindle, to simultaneously move the stabilizing member to the disk surface.
However, the following problem has been found in the above-described conventional apparatus: since the operation of moving the stabilizing member to the disk surface is performed simultaneously with the loading (or ejecting) of the magnetic disk serving as the recording medium, any dispersion in the quality of the parts constituting the mechanism or in that of the assembling work will cause the stabilizing member to exert force, while it is ascending together with the magnetic disk, against the magnetic disk before the magnetic disk has been completely loaded. Such premature application of force is apt to cause movements leading to damage to the recording surface of the magnetic disk. For example, the stabilizing member may deform the magnetic disk, or it may be brought into contact with the magnetic disk at a deviated position. Such an accident is most likely to occur when the magnetic disk is ejected before the stabilizing member has been separated from it. Any flaw in the magnetic disk constitutes a serious problem since it will deteriorate the accuracy of its rotation, thereby causing errors in the writing and reading of information.
Next, the system of supporting the stabilizing member in the above conventional apparatus will be discussed. The stabilizing member utilizes the airflow generated by the high-speed rotation of the magnetic disk so as to form an air film for pressing the magnetic disk against the magnetic head, thereby allowing it to run in a stable manner and providing a satisfactory head touch. Formed on that surface of this stabilizing member which faces the magnetic disk are projections, between which the magnetic head is placed. Defined between these projections is a recess or groove for allowing the magnetic head to move in the width direction in which the magnetic-head tracks are arranged. These projections help to stabilize the magnetic disk when it is being rotated.
The position of the magnetic head relative to these projections must be controlled with high accuracy within a range of several .mu.m. Accordingly, the position of protruding parts for mounting and adjusting this stabilizing member must also be controlled with similar accuracy with respect to the above-mentioned projections. In view of this, these protruding parts are equipped with an adjusting mechanism using screws or the like. When adjusting, those ridge sections of the projections which are nearer to the disk, for example, the ridge sections 252a and 252b in FIG. 8, which will be referred to below, are brought into contact with a measuring instrument, thereby adjusting the positions of these projections with respect to the head.
The above conventional example, however, involves the following problems: when the distance between the two projections is relatively small, it is very difficult to adjust with high accuracy the height of the protruding parts for mounting the stabilizing member by using, for example, the ridges of the projections as a reference. Moreover, a slight torsion in the two ridges will cause the stabilizing member to become unstable at the time of adjusting; the height of the protruding parts will also change if there is any dispersion in its mounting. As a result, the process of adjusting the head touch when incorporating the stabilizing member into the associated casing takes an excessively long time, making it very difficult to reduce labor and costs.
In addition, if the adjustment is repeated a number of times, the ridge sections, which are relatively weak, may be deformed or damaged. Thus, the above conventional system of adjustment is not desirable for a head-supporting mechanism, which requires high accuracy.
Stabilizing members of the type described above are disclosed, for example, in U.S. Pat. Nos. 4,787,005, 4,734,809, and 4,736,357, as well as in U.S. patent application Ser. No. 838,901 filed on Mar. 12, 1986 and 843,740 filed on Mar. 25, 1986.